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🔬general biology i review

Cleavage and polyadenylation specificity factor (CPSF)

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

CPSF is a multi-subunit protein complex that plays a crucial role in the post-transcriptional modification of eukaryotic mRNA by recognizing the polyadenylation signal and facilitating the cleavage of pre-mRNA at the correct site. This process is essential for generating mature mRNA molecules, which are critical for proper gene expression and regulation.

5 Must Know Facts For Your Next Test

  1. CPSF recognizes the AAUAAA sequence in the pre-mRNA as the polyadenylation signal, which is critical for cleavage and subsequent addition of the poly(A) tail.
  2. The CPSF complex consists of several subunits, each playing specific roles in recognizing the polyadenylation signal and mediating cleavage.
  3. CPSF interacts with other factors like CstF to ensure accurate cleavage and polyadenylation, highlighting its importance in coordinating multiple aspects of mRNA processing.
  4. Mutations in CPSF components can lead to defective mRNA processing, resulting in impaired gene expression and various diseases.
  5. The activity of CPSF is regulated by various signaling pathways and can be influenced by cellular conditions, making it a key player in controlling gene expression dynamics.

Review Questions

  • How does CPSF contribute to the maturation of pre-mRNA in eukaryotic cells?
    • CPSF is essential for the maturation of pre-mRNA as it recognizes the polyadenylation signal sequence (AAUAAA) within the transcript. Once bound to this sequence, CPSF facilitates the cleavage of pre-mRNA at the correct site, allowing for the addition of a poly(A) tail. This process is vital for producing stable and translatable mRNA molecules, ultimately influencing gene expression.
  • Discuss how CPSF interacts with other protein complexes during the cleavage and polyadenylation process.
    • CPSF works in conjunction with other protein complexes like Cleavage Stimulation Factor (CstF) during the cleavage and polyadenylation of pre-mRNA. The collaboration between these complexes ensures that cleavage occurs at precise locations. CstF helps determine where cleavage happens, while CPSF binds to the polyadenylation signal. Their interaction underscores the coordinated effort required for efficient mRNA processing.
  • Evaluate the impact of mutations in CPSF components on cellular processes and gene expression.
    • Mutations in CPSF components can severely disrupt the cleavage and polyadenylation of pre-mRNA, leading to improperly processed mRNA. This can result in reduced stability or translation efficiency of mRNA molecules, ultimately affecting protein synthesis. Such disruptions can contribute to various diseases by altering gene expression patterns, showcasing how critical CPSF is for normal cellular function and regulation.